Ji Wan Kim1, Jung Jae Kim2, Young-Soo Byun3, Oog-Jin Shon4, Hyoung Keun Oh5, Ki Chul Park6, Joon-Woo Kim7, Chang-Wug Oh8. 1. Haeundae Paik Hospital, Inje University, Busan, Republic of Korea. 2. Asan Medical Center, University of Ulsan, Seoul, Republic of Korea. 3. Daegu Fatima Hospital, Daegu, Republic of Korea. 4. Yeungnam University Hospital, Yeungnam University Medical Center, Daegu, Republic of Korea. 5. Ilsan Paik Hospital, Inje University, Koyang, Republic of Korea. 6. Hanyang University Guri Hospital, Hanyang University, Guri, Republic of Korea. 7. Kyungpook National Hospital, Kyungpook National University Hospital, Daegu, Republic of Korea. 8. Kyungpook National Hospital, Kyungpook National University Hospital, Daegu, Republic of Korea. Electronic address: cwoh@knu.ac.kr.
Abstract
INTRODUCTION: Many studies have tried to determine the characteristics of atypical femoral fractures (AFFs) through age-, sex-, and ethnicity-matched comparison with non-AFFs. However, we hypothesized that diaphyseal AFFs would have characteristics different from those of subtrochanteric AFFs. The aim of this study was to evaluate the clinical features of diaphyseal/subtrochanteric AFFs and determine the factors related to fracture location. PATIENTS AND METHODS: One hundred forty-seven patients with AFF were enrolled, 114 patients (78%) had a history of bisphosphonate use. Forty-nine patients (33%) had bilateral lesion, and 35% of patients had thigh pain. Patients were divided into two groups according to fracture location: 52 patients (35.4%) with subtrochanteric AFF and 95 patients (64.6%) with diaphyseal AFF. The patient demographics and fracture characteristics of the two groups were compared. Multivariate logistic regression analysis was used to adjust for variables related to fracture location. RESULTS: The patients in the diaphyseal AFFs group were older and had lower BMI, lower BMD, and larger lateral and anterior bowing. Multivariate analysis revealed that age greater than 65 years and low BMD were related with diaphyseal location. With greater lateral bowing angle, the AFF location was moved from the subtrochanteric area to the diaphyseal area. CONCLUSION: This study demonstrated that patients with diaphyseal AFFs had different characteristics compared with those with subtrochanteric AFFs.
INTRODUCTION: Many studies have tried to determine the characteristics of atypical femoral fractures (AFFs) through age-, sex-, and ethnicity-matched comparison with non-AFFs. However, we hypothesized that diaphyseal AFFs would have characteristics different from those of subtrochanteric AFFs. The aim of this study was to evaluate the clinical features of diaphyseal/subtrochanteric AFFs and determine the factors related to fracture location. PATIENTS AND METHODS: One hundred forty-seven patients with AFF were enrolled, 114 patients (78%) had a history of bisphosphonate use. Forty-nine patients (33%) had bilateral lesion, and 35% of patients had thigh pain. Patients were divided into two groups according to fracture location: 52 patients (35.4%) with subtrochanteric AFF and 95 patients (64.6%) with diaphyseal AFF. The patient demographics and fracture characteristics of the two groups were compared. Multivariate logistic regression analysis was used to adjust for variables related to fracture location. RESULTS: The patients in the diaphyseal AFFs group were older and had lower BMI, lower BMD, and larger lateral and anterior bowing. Multivariate analysis revealed that age greater than 65 years and low BMD were related with diaphyseal location. With greater lateral bowing angle, the AFF location was moved from the subtrochanteric area to the diaphyseal area. CONCLUSION: This study demonstrated that patients with diaphyseal AFFs had different characteristics compared with those with subtrochanteric AFFs.